This invention relates to a portable drum sander, particularly designed to be inexpensive and useful for a wide variety of sanding projects, such as scroll work and other small pieces, as well as larger projects where no limitation on the height of the workpiece is a condition. The sander operates in a manner similar to a jointer or planer, i.e., the workpiece is fed across the feed table and over an exposed sanding drum while applying sufficient pressure to maintain the workpiece firmly on the feed table. A simple height adjustment mechanism reduces cost and permits fast and accurate adjustment. The drum can be relatively wide, for example, 18 inches, and is sufficiently wide that as many as three different grits of sandpaper can be applied to different widthwise segments so that coarse, intermediate and finish sanding steps can be carried out in sequence without stopping the sander to change sandpaper. In many respects the drum sander operates like a belt sander.
Therefore, it is an object of the invention to provide a drum sander that operates like a jointer or planer.
It is another object of the invention to provide a drum sander that operates like a belt sander.
It is another object of the invention to provide a drum sander that has a simple height adjustment mechanism.
It is another object of the invention to provide a drum sander that can accommodate multiple sandpaper grades simultaneously.
It is another object of the invention to provide a drum sander that can accommodate workpieces with no height limitations.
It is another object of the invention to provide a drum sander that has a fixed offset between the height of the infeed table segment and the outfeed table segment.
These and other objects of the present invention are achieved in the preferred embodiments disclosed below by providing a portable drum sander comprising a base, a drum mounted for rotation on the base for carrying at least one grade of sandpaper on a peripheral surface thereof, and a feed table carried on the base and having a slot therein through which the drum is exposed for rotating contact with a workpiece to be sanded. The feed table includes an infeed table segment upstream of the slot and an outfeed table segment downstream of the slot for supporting the workpiece during passage over the slot in contact with the drum, and a pivot mounting the feed table adjacent a downstream end of the outfeed table segment for pivotal movement of the feed table to a desired height with reference to the drum. A height adjustment lock cooperates with the infeed table segment for locking the feed table into a locked position at the desired height with reference to the drum.
According to one preferred embodiment of the invention, a motor is mounted on the base and connected to the drum for supplying power to rotate the drum.
According to another preferred embodiment of the invention, the base comprises interconnected front, rear and left and right side plates forming a frame across which the drum extends and over which the feed table is mounted.
According to yet another preferred embodiment of the invention, the height adjustment lock comprises a lifter plate supporting the feed table and mounted for vertical movement relative to the front plate of the base for varying the height of the feed table within a range of vertical motion relative to the drum. At least one locking device is carried the front plate for locking the lifter plate into a desired position within the range of motion.
According to yet another preferred embodiment of the invention, the lifter plate supports the feed table adjacent an upstream end of the infeed segment of the feed table. The front plate includes at least one vertically-oriented slot, and the locking device comprises a bolt extending through the slot and threaded to the lifter plate, the bolt being rotatable between the locked position and an unlocked position for adjusting the height of the feed table.
According to yet another preferred embodiment of the invention, the lifter plate supports the feed table adjacent an upstream end of the infeed segment of the feed table. The front plate includes at least two laterally spaced-apart, vertically-oriented slots, and the locking device comprises at least first and second bolts extending, respectively, through the at least two slots and threaded to the lifter plate, the bolts each being rotatable between the locked position and an unlocked position for adjusting the height of the feed table.
Preferably, the locking device comprises three bolts extending, respectively, through three slots and threaded to the lifter plate, the bolts each being rotatable between the locked position and an unlocked position for adjusting the height of the feed table.
According to yet another preferred embodiment of the invention, the bolts include enlarged heads with peripheral indentations thereon for permitting manual rotation of the bolts.
According to yet another preferred embodiment of the invention, a dust port is positioned in one of the left or right side plates.
According to yet another preferred embodiment of the invention, the outer peripheral surface of the drum is covered with a multiplicity of closely-spaced flexible hooks for receiving sanding paper having a multiplicity of mating filament loops carried on the back thereof.
According to yet another preferred embodiment of the invention, the feed table is exposed for permitting sanding of workpieces without a height limitation.
According to yet another preferred embodiment of the invention, the drum is adapted for receiving and simultaneously carrying at least two different grades of sandpaper side-by-side for permitting first and second sanding steps to be carried out on the sander without changing sandpaper.
According to yet another preferred embodiment of the invention, the outfeed table segment is upwardly vertically offset relative to the infeed table segment.
According to yet another preferred embodiment of the invention, laterally-extending slots are provided in the infeed table segment and in the outfeed table segment for receiving a guide fence.